Scrolling a target window during a drag and drop operation

Abstract

A technique for transferring a graphical object in a graphical user interface on a computer display from a source window to a target window. It is determined that a graphical object from the source window has entered the target window during a drag and drop operation. Next, it is determined that the graphical object has hit an interior boundary of the target window. The target window is scrolled so long as the graphical object continues to hit the interior boundary. Once the target location is visible in the target window, the graphical object is located at the target location at conclusion of the drag and drop operation. The invention contemplates a graphical user interface in which some target windows are scrollable during a drag and drop operation with a graphical object from a foreign window, while some windows are not. Thus, in a mixed graphical user interface, it must be determined whether the target window is scrollable during a drag and drop operation.

We claim: 
     
       1. A method for transferring graphical objects in a graphical user interface on a computer display from a source window to a target window, comprising the steps of: during a first drag and drop operation in a first mode, determining that a first graphical object from the source window has hit an interior boundary of the target window, scrolling the target window so long as the first graphical object continues to hit the interior boundary and locating the first graphical object at a target location at a conclusion of the first drag and drop operation; and   during a second drag and drop operation in a second mode, which prevents the scrolling of the target window, dragging a second graphical object from the source window past an interior boundary of the target window.   
     
     
       2. The method as recited in claim 1 wherein the graphical user interface includes both scrollable and nonscrollable windows according to the method recited in claim 1 and the method further comprises the step of determining whether the target window is scrollable during a drag and drop operation where the graphical object originates from a source window. 
     
     
       3. The method as recited in claim 1 further comprising the steps of: storing an initial position of a pointer at commencement of the drag and drop operation to determine that the graphical object is foreign to the target window; and   refreshing a boundary position of the pointer as the foreign graphical object continues to hit the interior boundary of the target window.   
     
     
       4. The method as recited in claim 2 wherein the target window is determined to be scrollable by referring to a class of the target window. 
     
     
       5. The method as recited in claim 2 wherein the target window is determined to be scrollable by referring to a list of scrollable target windows. 
     
     
       6. A system for transferring a graphical object in a graphical user interface on a computer display from a source window to a target window, comprising: means for determining whether a drag and drop operation is in a first mode or a second mode;   means for determining that a graphical object from the source window has hit an interior boundary of the target window,   means responsive to a determination that the drag and drop operation is in the first mode for scrolling the target window so long as the graphical object continues to hit the interior boundary wherein the graphical object is located at a target location at a conclusion of the drag and drop operation; and   means responsive to a determination that the drag and drop operation is in the second mode, which prevents the scrolling of the target window, for dragging the graphical object past the interior boundary of the target window.   
     
     
       7. The system as recited ill claim 6 wherein the graphical user interface includes a set of scrollable windows, some but not all of which are scrollable during a drag and drop operation responsive to a foregin graphical object at an interior boundary and the system further comprises means for determining whether the target window is scrollable during a drag and drop operation responsive to the foreign graphical object being at an interior boundary. 
     
     
       8. The system as recited in claim 6 further comprising: means for storing an initial position of a pointer at commencement of the drag and drop operation to determine that the graphical object is foreign to the target window; and   means for refreshing a boundary position of the pointer as the foreign graphical object continues to hit the interior boundary of the target window.   
     
     
       9. The system as recited in claim 7 wherein the target window is determined to be scrollable by referring to a class of the target window. 
     
     
       10. The system as recited in claim 7 wherein the target window is determined to be scrollable by referring to a list of scrollable target windows. 
     
     
       11. The system as recited in claim 6 which further comprises: a memory coupled to a system bus for storing sets of instructions to operate the system;   a processor coupled to the system bus to execute the sets of instructions; and   a display coupled to the system bus for displaying the graphical user interface.   
     
     
       12. A computer program product in a computer readable memory for transferring a graphical object in a graphical user interface on a computer display from a source window to a target window, comprising: means for determining whether a drag and drop operation is in a first mode or a second mode;   means for determining that a graphical object from the source window is present at an interior boundary of the target window;   means responsive to a determination that the drag and drop operation is in the first mode for scrolling the target window so long as the graphical object is at the interior boundary wherein the graphical object is located at a target location at a conclusion of the drag and drop operation; and   means responsive to a determination that the drag and drop operation is in the second mode, which prevents the scrolling of the target window, for dragging the graphical object past the interior boundary of the target window.   
     
     
       13. The product as recited in claim 12 wherein the graphical user interface contains scrollable windows according to a variety of user interactions and that only some of the scrollable windows scroll responsive to a presence of a foreign graphical object at an interior boundary during a drag and drop operation and the product further comprises means for determining whether the target window is scrollable during a drag and drop operation responsive to a foreign graphical object being at an interior boundary. 
     
     
       14. The product as recited in claim 12 further comprising: means for storing an initial position of a pointer at commencement of the drag and drop operation to determine that the graphical object is foreign to the target window; and   means for refreshing a boundary position of the pointer as the foreign graphical object continues to hit the interior boundary.   
     
     
       15. The product as recited in claim 13 wherein the target window is determined to be scrollable by referring to a class of the target window. 
     
     
       16. The product as recited in claim 13 wherein the target window is determined to be scrollable by referring to a list of scrollable target windows.